SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3acda6f7602630db6fd9e5172d61f04e449c3d72af58afdc49d8119fa18adbd4' 
  AND token = 'F0nkzw9Fqt/I4+blVJwQdhcCVSYAohcPbGGG6QnT3gg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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