SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f83d7b0ff4131774294711f0d67288d32a31bd5d1032c095db313b85fffff9b8' 
  AND token = '6u5PqfwL5Z3i3Q2avdqavUR0iMWcTyrZjBwzkJltNkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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