SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e1a7c1aa67874730d9090bd57a132902c870681a984ace39b29877a307bd994' 
  AND token = 'UhTcbklJotJjoOszYVZM4C3ZwO1ClzyphkNP59cFxRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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