SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b0fb7704eb70118739d4ff8a83e91bc6e56603470dc9d4bcf6f90cc59a33045' 
  AND token = 'o8TfZj8NrlClE/y31IWRujLILEiyFfGEf6AkgWKLB14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}