SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8543ac2f978dec5cd5b7582e4d6380672fd5365786420f5e90e06dea60a3dd97' 
  AND token = '/g2SEk0llzKEMn1cAySkEkYAi0Xtv1cRddanlinpXmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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