SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd17634b33483fe670312cdc5979e0f0755874a9818170bf81478163300d6e9ce' 
  AND token = '1AcMMWQggHbXeFmIieOZaql3t99kPllQ/6zVQmpOCNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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