SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '494f7f3430cdb1b29000c13dc0939146078770cefc20c9319e3d391b72e8cbdf' 
  AND token = 'ZdLLv/gyfylAkBzgnk/+31oBUTyswjmNACe1Q8QKekg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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