SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9128b0716937ac4fa606cdd18823b693b58df3b38be1f44ab5246a1b28988795' 
  AND token = 'yDIpgWug7poT/zr3Oxcielqp342Fnt3SXNnZkglOvpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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