SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e44cef398a3cb72c7a7d9249435faa459a98319876bebfd3d37d9df55b4b26' 
  AND token = 'mzdXlgzkZqCh+k+vyqFpPuwFscjUwv2lb5H7QnuU6/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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