SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '619861ffb90234d2ee19347c9e80216f0971b7c18763f2f20562f45608cb807f' 
  AND token = 'nFLV6u8kCQZmGS1sUlp4CtRk5U7FwpqPvg9ChfA8ABI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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