SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80c97b4cb544ce2849e546012c79439babf6f9d2c23585b66ab8c051238dcb11' 
  AND token = 'YCB1V0hBAbFn17/zEuIOzfTO+IoFAEpxcbAbT1+vbcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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