SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f9909fa9b167984e40839209821fa4b6b3132d8473bda0a2a70677794b0eda2' 
  AND token = 'n1Dpfod0mbVfqCSBUYAcNC8gJ5nOwXZ9thhHVv/TG+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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