SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '536243d426b9ae096c94c309d8dc3375700b2ab20afb6a1bec6a747af6a67cf7' 
  AND token = 'uKHGIYzzVOZz1Z/URPXiripzRSUskaGEKe0ECcDDeZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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