SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ce01f8e1820ff6a0773d637c455e139988561b244f9cb39cdf02ccd1ccd3a2e' 
  AND token = 'ATwTgdMyudlUejrzL+KQ9x+C4k+zvnXxqhcFqeG/hUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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