SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c322d08473113890e2a38502ddf96d84f7d4f466ea30188d3fca12dd4754351' 
  AND token = 'eibWu8W8pTKYreKtU9ykl6xEaOwiKS8rP6G2nfGDqmQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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