SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2541b92083f4e6387ef57e9ef016d32b69602bae3478e9487ddaa2760ef3ea3e' 
  AND token = 'SM+c08OFvZ2vG3UM1kb3LB9IJk+P08jdSHxNvD0gUqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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