SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adad345a9cf069a1ace1c2792ca0cdf3e18c1cbd914c7153afa2a1d0fb278352' 
  AND token = 'Myfzdo1/wzPxUgc5DLwpxmAWDKVPNfts5AxpIJoKm6M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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