SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb95857a018a67f30aa27bfd5b8ef5297f14c01e9760a6d1e67a96845b2c261' 
  AND token = 'No6JP4ZR2n6h55Dr2wsJFgsTSD4f9MaGXsJThQtWZcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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