SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02b628276067f391016767e2c117a63070f09cb0e61e7378d012c1e5b3a8ae20' 
  AND token = 'isT8mG+J8VOlEexqGX5zm6Mgdjzw1p1plzwgULOTnbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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