SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d292456a19ba6cc0e9665e4d4d4ca2992ae5459fab73b708de78806a183c44b' 
  AND token = 'vvy1gFYDIpwI7LUHwMCkT2j4tSj5f60sj4aO3o0jgmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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