SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'db9cc747d7c9a81b0da20cd4bb25190da5c9c6fe5e363574b68cc40e8f2d7cf4' 
  AND token = 'QNx5zZTn6Tyo9pW7j3yMPPT2aabjvXrH8HoDMoM0Spo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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