SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd534ec1a598af40e152df15b77ee50c5069f42c8016698630ecce034cbd0c7ec' 
  AND token = 'BXihMMnjHfQh2Ci2ZbDSKL/XayEJ1Kaap7QszoJfHoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}