SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbadc426028a392c471fa5ef6c97b3627cc9d975b0b75f19dc31fb856f393157' 
  AND token = 'zagbHDcSV9BNljUNsKVpHW9QvweIbc+rhg62AhIzVD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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