SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3125cbedfd03f745bfbed36e2c226934060d1ccb7b91fe8b33967cacc3edeff6' 
  AND token = 'r02RdDWAIgriD1NMQAj2Eovu5otiyCWWqTnVvdsVS1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00091

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}