SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c9bbfbe1ba003f8f8e7bf871ceed92d73d3ac57d91187533295223ec67686e3' 
  AND token = 'DwmOoZ2uJt7+I9X5/pBTlnrzjBfUN4/qG6GCedZWxzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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