SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8037506dccb6853a6b47645437b0d3b9d6d2b240c85435b536648b73730fb654' 
  AND token = 'L4182suteUYwQpvEIY+dbI16ltpAPWKD9iM2YV1bu10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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