SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fe88c03267d9c587c215e4a804d745826d8719b5364c849ddc281de53f902b5' 
  AND token = 'T+IOOThUrSRonKlsHKsR33Q5fT854zGe1WUurXbTdoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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