SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b559a376f5769245de8142b8565d01c408038c84556b8ead82f7ffa44fee011' 
  AND token = 'h37lWV4S77mgkEKa/gBQWpDJkukR63g/aiKA5LRGqyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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