SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ee05902b0a521221f2bf7f4ad346ba9aac5e1ced66ba37488ef9a06f747ed31' 
  AND token = 'rpk/rwnibdzHLPE1Qa3denDE6t+lDjGR0Y31VPNjWfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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