SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52710932eb8e5239d4b94778cd55b1c2923cc196e215dba8fe2c597f64c3c22' 
  AND token = 'cSzHNVLwvAReJpOfkTxApBlMYbh+Y5oqKzDN9iDNrfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00077

JSON explain

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