SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ccc57c711c9e1ff91ceacd35e90ecb3d62baea2ebbd29c6b25c2409209039c8a' 
  AND token = 'yJDBtjQLRqT7RVwMr9ebdjLF0eEqM7V/tzYjtPPeO4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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