SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3969fb5fff3fed3429b22b81d206c1c54da86379d64a42f647ee4f16a935103' 
  AND token = 'TZtWjq43ztNDSdfAUW3NmK2fVnJDqNZt8JuvL3kVn14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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