SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bc61b5aab788bdf5da51a5cc9e6e0b75e4025af6d26e46cdc65f3213bc0950f0' 
  AND token = 'BtXly8PUvmFLq8QKtXLdCKp/P279G1jyyxXl6Sq4XQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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