SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bae8136de32552d2bc70d808a12fbd336e61839002aa17a220114fa8b8d9e338' 
  AND token = 'rrSugG+Q8PWauGlKxmUEMHYKaa5BSMWMC2yf9VbX1Ck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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