SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b34456a5c7d68b06746c2dae303181625c8165d346b54422cf3880ae3cf6bcba' 
  AND token = 'Fq0Pnmr83Qy5fUkjymEYM0WpN/NIkw82n6umDLHXOiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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