SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b59762bdb2685936daca963bfe43fec24a6b5bb1922d7f17001cc2fb62cc4824' 
  AND token = 'cYXNjZPditGhNll/y13m9L/+qa+8Qba6ybzQPEhCSzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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