SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cdac558d03abc03665679bdf98bfe9355b345b0e59cf3b94d3f500e7f1b5b1c' 
  AND token = 'ijCbmsFdcdADqxGCX3QdiYsDuAv71KTmENCkvYwdZUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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