SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84fb9bf86d2d553419cdefef4a78e3cb9525c131df75cf2b1fb94ed71e387f80' 
  AND token = 'cjpopBSjogotHxdhIqkhAvmwhvjI/TDZ8QuflCwQ3G4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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