SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd70527cb0e007762a830d8c4c58d1f1f60271f694fd265255cd2a93013554e23' 
  AND token = 'ZHpmeFjuxtEvEgvnIhandeygAnLv3nGhmmkPSMI8E3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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