SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41e9422678b55b4e30fa4c0f1ef00457c0da9caec9874183a78de0402698d4ba' 
  AND token = 'UNqoDgH3aaCIDL3ZHfaJ+FGj5HOmB5QbI3z/lM+j6EU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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