SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c4138d4d7aa4dd3a1bff5a86f8f66eef1da1ea45fcfe0cf85ecce0815310972' 
  AND token = 'FTdbJwchqLjLAfFJFgorjQKe7YWK61Zf3R81//OAFzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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